* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 设置整体页面高度 */
body {
    height: 100%;
    background-image: url(https://img0.baidu.com/it/u=53343021,1423959749&fm=253&fmt=auto&app=138&f=JPEG?w=667&h=500);
    background-position: center;
    background-size: cover;
    background-repeat: no-repeat;

}
/* 上方导航栏 */
.main {
    width: 100%;
    height: 50px;
    background-color: rgba(100, 150, 255, 0.4);
    color: #fff;

    display: flex;
    justify-content: left;
    align-items: center;

}
/* 导航栏中的按钮 */
.main a {
    font-size:20px;/*设置字体大小*/
    text-align:center;/*字体居中*/
    text-decoration: none;
    padding: 50px 50px;
}
/* 导航栏中的占位器 */
.main .spacer {
    width: 70%;
}

.container {
    display:inline-block;
    /* 使用 calc 计算高度 */
    height: calc(100% - 50px);
    padding: 10px 20px ;
    display: flex;
    justify-content: flex-start;/*左对齐*/
    align-items: center;
    flex-wrap:wrap;/*允许超过页面距离时换行*/
}

.change{
 padding:10px 18px 10px 26px;
}
.change h1{
    font-size:1.5em;
    display: flex;
    justify-content: center;
    align-items: center;
}
.change h1 a{
     text-decoration:none;/*去下划线*/
}
.pchange{/*p标签的class*/
     text-align:center;
}

